This invention relates to a watercraft and more particularly to several improved features of watercraft.
A wide variety of types of watercraft are utilized. In any watercraft that employs an inboard mounted engine, it is desirable to ensure that the engine compartment is well ventilated. This is particularly true with the types of watercraft wherein the engine is contained in an enclosed bilge area. In order to ensure safety, good engine performance and for a variety of other reasons, it is desirable to ensure proper ventilation of the engine compartment.
With many types of watercraft, particularly larger ones, it is very easy to provide a ventilation system that can employ one or more fans for circulating ventilating air. However, there is a type of watercraft called the "personal watercraft" that are much more compact in nature and in which the ventilation of the engine compartment is not as easy. Because of the small nature of these watercraft, the use of ventilating fans is not practical since the watercraft may either not have a battery for driving the fan or may be so compact in nature that fan type ventilation is not practical. Thus, another type of system must be employed to ensure the free flow of ventilating air through the engine compartment.
It is, therefore, a first principal object of this invention to provide an improved ventilating system for the engine compartment of a small watercraft.
It is a further object of this invention to provide an improved ventilating system for a small watercraft wherein positive ventilation flow can be accomplished when the watercraft is in motion and which does not require fans for air circulation.
In conjunction with a wide variety of watercraft, it is well known that the speed and performance of the watercraft can be increased by decreasing the wetted area on the underside of the hull. However, various hull configurations are employed and in many instances it may not be desirable to reduce the hull wetted area too greatly. It is, nevertheless, desirable to employ an arrangement for reducing the water resistance. One way in which this is done is to provide a step in the hull under surface and to draw air into the step area so as to mix with the water and reduce the frictional resistance between the watercraft and the hull area. However, with small personal type watercraft this feature is also difficult to accomplish.
It is, therefore, a still further object of this invention to provide a hull undersurface wherein the flow resistance of the water along the hull surface can be reduced.
One particularly popular type of personal watercraft employs a jet propulsion unit for its mode of power. Frequently, the jet propulsion unit is mounted at least in substantial part in a tunnel formed beneath the watercraft. With this type of arrangement it has been difficult to provide a step arrangement for reducing hull resistance.
It is, therefore, a still further principal object of this invention to provide an improved hull configuration for a jet propelled watercraft wherein the flow resistance can be reduced with a relatively simple construction.
In jet propelled personal watercraft of the type aforenoted, the mounting of the jet propulsion unit within the tunnel presents certain problems. Normally, it has been the practice to suspend the jet propulsion unit at least in part from above within the tunnel. However, this type of support requires a relatively thick tunnel wall area and this can undesirably add to the weight of the watercraft.
It is, therefore, another principal object of this invention to provide an improved arrangement for mounting the jet propulsion unit within the tunnel of a small watercraft.
In conjunction with accomplishing the aforenoted feature, it is a further object of this invention to provide a mounting arrangement which will also permit the use of a step for reducing water resistance.
In addition to the problems already discussed, with small personal type watercraft it is also desirable to provide a very effective exhaust treatment for discharging the exhaust gases to the atmosphere, silencing the exhaust gases and preventing the entry of water into the engine through the exhaust ports from the exhaust system. As the watercraft becomes smaller and more compact, the achievement of these goals is difficult.
Many of the small personal type watercraft employ a seat that accommodates the rider and possibly additional passengers seated in straddle fashion and when plural riders are accommodated they are seated in tandem fashion. This requires a provision of a pair of relatively low foot areas so that the riders can be seated comfortably and this reduces the area in which the engine, propulsion unit and exhaust system can be employed. In order to accommodate this situation, it has been proposed to mount the engine either forwardly of the seat or under the forward portion of the seat. Where either of these expedients are employed, an expansion chamber is normally positioned forwardly of the engine, if the engine is under the seat, or to one side of the engine, if it is forwardly of the seat, and then discharge the exhaust gases at a forward location.
Such an arrangement has a number of disadvantages. First, it tends to concentrate too much weight at the front of the watercraft if a forward engine compartment is employed. In addition, the forward discharge of the exhaust gases can cause the operator and riders to be subject to the fumes from the exhaust gases and this is not desirable. In addition, the forward discharge of the exhaust gases tends to cause sound to emanate to the passengers.
It is, therefore, a still further principal object of this invention to provide an improved exhaust system for a small watercraft.
It is another object of the invention to provide an exhaust system for a small watercraft wherein the exhaust system can be positioned at least in major part beneath the seat and the weight of the engine and the exhaust system can be positioned more centrally in the watercraft in the longitudinal direction.
As has been noted, the small personal watercraft of the type described normally employ a seating arrangement wherein the rider and possibly one or more passengers are seated in straddle fashion. Where this is done and where plural riders are accommodated, it is advantageous if the rear rider can have his head positioned slightly above that of the forward rider. In this way, the rear rider has the forward view. However, due to the small nature of these watercraft, this means that the rear positioned rider has nothing to grip in order to steady himself.
It is, therefore, a further principal object of this invention to provide a seating arrangement for a small watercraft wherein a pair of handles can be easily provided at the rear of the seat.
The type of watercraft described and particularly most personal type of watercraft generally have a passenger's area that opens through the transom of the watercraft so that the watercraft can be boarded from the body of water in which the watercraft is operating. However, it is desirable to provide some means to assist the passenger to enter the watercraft.
It is, therefore a still further object of this invention to provide an improved grab handle arrangement for the rear portion of a small watercraft for assisting entry of the watercraft at the rear from the body of water in which the watercraft is operating.
Again, in connection with the seating of these watercraft, when a straddle-type seat is employed and regardless of the number of riders accommodated, the control of the watercraft is normally positioned to the front of the seat. There are times when it may be desirable to accommodate a smaller person such as a child. If the child is seated behind the operator, then the child cannot see forwardly and also it is difficult for the rider to determine the condition of the child. Therefore, there is some desire to accommodate a child at the front of the operator between the operator and the control. However, when this is done, there must be some assurance that the child will have a way of holding himself in position and will not be likely to attempt to grab the controls to obtain stability.
It is, therefore, a still further principal object of this invention to provide an improved seating and grab handle arrangement for a small watercraft wherein a child may be seated forwardly of the rider and is provided with a grab handle independently of the control for the watercraft.
With many of the types of personal watercraft as described, the watercraft is very sporting in nature and the riders normally operate the watercraft or ride on it in swimming suits. As has been noted from the previous discussion, frequently the riders will enter the watercraft through the rear via an open transom. In addition, it is not uncommon for this type of watercraft to become either partially or fully capsized. Many of these watercraft are designed so as to be self-righting while others are not self-righting. Regardless of whether the watercraft is of the self-riding or non self-righting type, certain problems may be encountered with the engine if the watercraft is inverted. This is particularly true if the watercraft is powered by the a four-cycle engine which type of engine normally incorporates a crankcase in which a volume of lubricant is maintained with the lubricant being circulated through the engine for its lubrication.
With this type of arrangement, if the watercraft becomes inverted and remains inverted for a period of time, the lubricant may flow from the crankcase chamber through drain passages into the cylinder head and cam drive arrangement. This can cause the crankcase chamber to be depleted from lubricant. Thus, if the watercraft is subsequently righted and an attempt is made to start the engine quickly thereafter, there may be no lubricant in the crankcase for engine lubrication and damage can obviously result.
It is, therefore, a still further principal object of this invention to provide an arrangement for a small watercraft powered by a four-cycle engine wherein at least some lubricant is trapped in the crankcase chamber upon inversion so as to ensure that there will be lubricant in the crankcase chamber for lubrication purposes if the engine is started immediately upon righting.